CSS performance, L18n, Popups, Searchbox vs Comments, Icons

* CSS performance; for anonymous users the CSS applies faster while
loading page. Also for logged in users the CSS applies slightly faster
(for logged on users the speed can be further improved)
* Popups; now have max-width function
* Comments; messed up DOM elements with class "nxs-form"; interfered
with Searchbox (caused Searchbox to be hidden)
* Defined various icons for the widgets